Water is one of the most vital components for all forms of life and is indispensable to the maintenance of life on the earth. Water may be contaminated by natural sources or by industrial effluents. One of such contaminants is fluoride as it has a profound effect on teeth and bones when the concentration in drinking waters exceeds the permitted limits. Concentrations in the range of 1.0-1.5 mg/lit strengthens the enamel and in the range of 1.5-4.0 mg/lit results dental fluorosis whereas with prolonged exposure to higher concentrations (4-10 mg/lit) results skeletal fluorosis in children as well as adults. The fluoride concentrations in groundwater more than 30 mg/lit occur widely in many parts of the world such as India, Pakistan, West Africa, Thailand, China, Sri Lanka, Southern Africa, United States of America, Argentina, and Ethiopia. This article reviews the present scenario of groundwater pollution and a number of adverse effects on health caused by fluoride ions.